(2025\2026) COMPREHENSIVE
QUESTIONS & VERIFIED ANSWERS
What are clinical manifestations of hypothyroidism? - correct answer Constipation, decreased heat rate,
and lethargy
Thyroid-stimulating hormone (TSH) is released to stimulate thyroid hormone (TH) and is inhibited when
plasma levels of TH are adequate. This is an example of: - correct answer Negative feedback. Feedback
systems provide precise monitoring and control of the cellular environment. Negative feedback occurs
because the changing chemical, neural, or endocrine response to a stimulus negates the initiating
change that triggered the release of the hormone.
Lipid-soluble hormone receptors are located: - correct answer Inside the plasma membrane in the
cytoplasm.
The releasing hormones that are made in the hypothalamus travel to the anterior pituitary via the: -
correct answer Portal hypophyseal blood vessels.
Which mineral is needed for thyroid-stimulating hormone (TSH) to stimulate the secretion of thyroid
hormone (TH)? - correct answer Iodide.
What effect does hyperphosphatemia have on other electrolytes? - correct answer Decreases serum
calcium.
Insulin transports which electrolyte in the cell? - correct answer Potassium.
Which second messenger is stimulated by epinephrine binding to a β-adrenergic receptor? - correct
answer Cyclic adenosine monophosphate (cAMP). Second-messenger molecules are the initial link
between the first signal (hormone) and the inside of the cell. For example, the binding of epinephrine to
a β adrenergic-receptor subtype activates (through a stimulatory G protein) the enzyme, adenylyl
,cyclase. Adenylyl cyclase catalyzes the conversion of adenosine triphosphate (ATP) to the second
messenger, 3', and 5'-cAMP.
Regulation of the release of catecholamines from the adrenal medulla is an example of which type of
regulation? - correct answer Neural. The release of hormones occurs either in response to an alteration in
the cellular environment or in the process of maintaining a regulated level of certain hormones or
certain substances. Several different mechanisms, one of which is neural control (e.g., stress-induced
release of catecholamines from the adrenal medulla), regulate the release of hormones.
Which hormone does the second messenger calcium (Ca++) bind to activate phospholipase C through a
G protein? - correct answer Angiotensin II. Ca++ is considered an important second messenger that
facilitates the binding of a hormone (e.g., norepinephrine, angiotensin II) to a surface receptor,
activating the enzyme phospholipase C through a G protein inside the plasma membrane.
The control of calcium in cells is important because it: - correct answer Acts as a second messenger. In
addition to being an important ion that participates in a multitude of cellular actions, Ca++ is considered
an important second messenger.
Where is antidiuretic hormone (ADH) synthesized, and where does it act? - correct answer Hypothalamus;
renal tubular cells. Once synthesized in the hypothalamus, ADH acts on the vasopressin 2 (V2) receptors
of the renal duct cells to increase their permeability.
How does a faulty negative-feedback mechanism result in a hormonal imbalance? - correct answer
Excessive hormone production results from a failure to turn off the system. Negative- feedback systems
are important in maintaining hormones within physiologic ranges. The lack of negative-feedback
inhibition on hormonal release often results in pathologic conditions. Excessive hormone production,
which is the result of the failure to turn off the system, can cause various hormonal imbalances and
related conditions.
A deficiency of which chemical may result in hypothyroidism? - correct answer Iodine. The only cause of
hypothyroidism from among the provided options is a deficiency of endemic iodine.
What imbalance lessens the rate of secretion of parathyroid hormone - correct answer The overall effect
of parathyroid hormone (PTH)is to increase serum calcium and to decrease serum phosphate
concentration.
, Which condition may result from pressure exerted by a pituitary tumor? - correct answer
Hypothyroidism. If the tumor exerts sufficient pressure, then thyroid and adrenal hypofunction may
occur because of lack of thyroid-stimulating hormone (TSH) and adrenocorticotropic hormone (ACTH).
These result in the symptoms of hypothyroidism and hypocortisolism.
Which substance is a water-soluble protein hormone? - correct answer Insulin. Peptide or protein
hormones, such as insulin, pituitary, hypothalamic, and parathyroid, are water soluble and circulate in
free (unbound) forms.
Which of the following is a lipid-soluble hormone? - correct answer Cortisol. Cortisol and adrenal
androgens are lipid-soluble hormones and are primarily bound to a carrier or transport protein in
circulation.
Most protein hormones are transported in the bloodstream and are: - correct answer Free in an
unbound, water-soluble form. Peptide or protein hormones, such as insulin, pituitary, hypothalamic, and
parathyroid, are water soluble and circulate in free (unbound) forms.
When insulin binds its receptors on muscle cells, an increase in glucose uptake by the muscle cells is the
result. This is an example of what type of effect by a hormone? - correct answer Direct. Direct effects are
the obvious changes in cell function that specifically result from the stimulation by a particular hormone.
Graves disease develops from a(n): - correct answer Thyroid-stimulating immunoglobulin that causes the
overproduction of thyroid hormones. The pathologic features of Graves disease indicates that normal
regulatory mechanisms are overridden by abnormal immunologic mechanisms that result in the
stimulation of excessive TH.
Pathologic changes associated with Graves disease include: - correct answer High levels of circulating
thyroid-stimulating immunoglobulins. The only option that correctly describes the changes associated
with Graves disease identifies high levels of circulating thyroid-stimulating immunoglobulins that are
found in more than 95% of individuals diagnosed with the disease.
The signs of thyrotoxic crisis include: - correct answer Hyperthermia and tachycardia